Your search found 3 records
1 Yalew, S.; Pilz, T.; Schweitzer, C.; Liersch, S.; van der Kwast, J.; Mul, Marloes L.; van Griensven, A.; van der Zaag, P. 2014. Dynamic feedback between land-use and hydrology for ecosystem services assessment. In Ames, D.P., Quinn, N.W.T., Rizzoli, A.E. (Eds.). Proceedings of the 7th International Congress on Environmental Modelling and Software, San Diego, California, USA, 15-19 June 2014. Manno, Switzerland: International Environmental Modelling and Software Society (iEMSs). 8p.
Hydrology ; Ecosystem services ; Land use ; Catchment areas ; Grasslands ; Biomass ; Soils ; Case studies / South Africa / uThukela Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H046491)
http://www.iemss.org/sites/iemss2014/papers/iemss2014_submission_255.pdf
https://vlibrary.iwmi.org/pdf/H046491.pdf
https://vlibrary.iwmi.org/pdf/H046491.pdf
(0.48 MB) (495.82 KB)
Ecosystem services assessment requires an integrated approach, as it is influenced by elements such as climate, hydrology and socio-economics, which in turn influence each other. However, there are few studies that integrate these elements in order to assess ecosystem services. Absence of integrated approach to modelling hydrological and land-use changes, for instance, often oversights the dynamic feedback between the two processes. Dynamic changes in land-use should be fed into hydrological models and vice-versa at each time-step for a more realistic representation. In this study, this approach is demonstrated with a case study of the uThukela catchment, South Africa. There is an increasing pressure on grasslands in the catchment. The grassland supports livestock grazing, one of the main economic and social service for the communal farmers. High livestock population causes degradation of the grasslands, and increasing demand for agricultural lands decreases the extent of the grazing lands. In addition, this is further influenced by changes in climate, and has multiple impacts, such as increased erosion and changing flow regime. The SITE (SImulation of Terrestrial Environments) land-use change model and the SWIM (Soil and Water Integrated Model) hydrological model were coupled at code level to account for these processes. The two models exchange land-use maps (from SITE) and biomass production (from SWIM). SWIM was modified to produce biomass output. Grassland capacity for grazing service is determined through biomass coming from SWIM. Likewise, the simulated land-use change is passed back to the hydrological model to determine effects of land-use change on hydrological components. Preliminary result of the interactions between the two models and its use for estimating grazing capacity show that through the coupled models, sustainable level of grassland grazing locations were easily identifiable.
2 Reinhardt, J.; Liersch, S.; Abdeladhim, M. A.; Diallo, M.; Dickens, Chris; Fournet, S.; Hattermann, F. F.; Kabaseke, C.; Muhumuza, M.; Mul, Marloes L.; Pilz, T.; Otto, I. M.; Walz, A. 2018. Systematic evaluation of scenario assessments supporting sustainable integrated natural resources management: evidence from four case studies in Africa. Ecology and Society, 23(1):1-34. [doi: https://doi.org/10.5751/ES-09728-230105]
Natural resources management ; Participatory research ; Sustainability ; Assessment ; Stakeholders ; Watersheds ; River basins ; Political aspects ; Case studies / South Africa / Tunisia / Uganda / Mali / Oum Zessar Watershed / Rwenzori Region / Inner Niger Delta / Upper Thukela Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048530)
https://www.ecologyandsociety.org/vol23/iss1/art5/ES-2017-9728.pdf
https://vlibrary.iwmi.org/pdf/H048530.pdf
https://vlibrary.iwmi.org/pdf/H048530.pdf
(2.43 MB)
Scenarios have become a key tool for supporting sustainability research on regional and global change. In this study we evaluate four regional scenario assessments: first, to explore a number of research challenges related to sustainability science and, second, to contribute to sustainability research in the specific case studies. The four case studies used commonly applied scenario approaches that are (i) a story and simulation approach with stakeholder participation in the Oum Zessar watershed, Tunisia, (ii) a participatory scenario exploration in the Rwenzori region, Uganda, (iii) a model-based prepolicy study in the Inner Niger Delta, Mali, and (iv) a model coupling-based scenario analysis in upper Thukela basin, South Africa. The scenario assessments are evaluated against a set of known challenges in sustainability science, with each challenge represented by two indicators, complemented by a survey carried out on the perception of the scenario assessments within the case study regions. The results show that all types of scenario assessments address many sustainability challenges, but that the more complex ones based on story and simulation and model coupling are the most comprehensive. The study highlights the need to investigate abrupt system changes as well as governmental and political factors as important sources of uncertainty. For an in-depth analysis of these issues, the use of qualitative approaches and an active engagement of local stakeholders are suggested. Studying ecological thresholds for the regional scale is recommended to support research on regional sustainability. The evaluation of the scenario processes and outcomes by local researchers indicates the most transparent scenario assessments as the most useful. Focused, straightforward, yet iterative scenario assessments can be very relevant by contributing information to selected sustainability problems.
3 Yalew, S. G.; Pilz, T.; Schweitzer, C.; Liersch, S.; van der Kwast, J.; van Griensven, A.; Mul, Marloes L.; Dickens, Chris; van der Zaag, P. 2018. Coupling land-use change and hydrologic models for quantification of catchment ecosystem services. Environmental Modelling and Software, 109: 315-328. [doi: https://doi.org/10.1016/j.envsoft.2018.08.029]
Ecosystem services ; Catchment areas ; Land use ; Hydrological factors ; Models ; Couplings ; Calibration ; Environmental assessment ; Stream flow ; Biomass ; Grasslands ; Grazing lands
(Location: IWMI HQ Call no: e-copy only Record No: H048890)
Representation of land-use and hydrologic interactions in respective models has traditionally been problematic. The use of static land-use in most hydrologic models or that of the use of simple hydrologic proxies in land-use change models call for more integrated approaches. The objective of this study is to assess whether dynamic feedback between land-use change and hydrology can (1) improve model performances, and/or (2) produce a more realistic quantification of ecosystem services. To test this, we coupled a land-use change model and a hydrologic mode. First, the land-use change and the hydrologic models were separately developed and calibrated. Then, the two models were dynamically coupled to exchange data at yearly time-steps. The approach is applied to a catchment in South Africa. Performance of coupled models when compared to the uncoupled models were marginal, but the coupled models excelled at the quantification of catchment ecosystem services more robustly.
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